Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities:
Cash receipts from customers	$ 63,751	$ 58,873
Cash paid for inventory and prescriptions dispensed by retail network pharmacies	(36,969)	(35,645)
Insurance benefits paid	(14,303)	(12,951)
Cash paid to other suppliers and employees	(8,187)	(7,403)
Interest and investment income received	206	250
Interest paid	(1,128)	(1,123)
Income taxes paid	(65)	(53)
Net cash provided by operating activities	3,305	1,948
Cash flows from investing activities:
Proceeds from sales and maturities of investments	1,288	1,986
Purchases of investments	(1,535)	(2,047)
Purchases of property and equipment	(742)	(716)
Acquisitions (net of cash acquired)	(613)	(124)
Other	5	10
Net cash used in investing activities	(1,597)	(891)
Cash flows from financing activities:
Net borrowings of short-term debt	255	2,285
Proceeds from issuance of long-term debt	3,946	0
Repayments of long-term debt	(1,008)	(882)
Dividends paid	(652)	(649)
Proceeds from exercise of stock options	154	101
Payments for taxes related to net share settlement of equity awards	(16)	(44)
Other	(4)	5
Net cash provided by financing activities	2,675	816
Net increase in cash, cash equivalents and restricted cash	4,383	1,873
Cash, cash equivalents and restricted cash at the beginning of the period	5,954	4,295
Cash, cash equivalents and restricted cash at the end of the period	10,337	6,168
Reconciliation of net income to net cash provided by operating activities:
Net income	2,012	1,427
Adjustments required to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	1,086	1,111
Stock-based compensation	96	114
Deferred income taxes and other noncash items	(35)	153
Change in operating assets and liabilities, net of effects from acquisitions:
Accounts receivable, net	(2,715)	(1,989)
Inventories	541	1,001
Other assets	(1,119)	(389)
Accounts payable and pharmacy claims and discounts payable	1,928	(22)
Health care costs payable and other insurance liabilities	139	553
Other liabilities	1,372	(11)
Net cash provided by operating activities	$ 3,305	$ 1,948